Glassware inspection apparatus employing fiber-optic guides

ABSTRACT

Optical glassware inspection apparatus with rotating upright ware at an inspection station and fiber-optic bundles employed for light source and/or reflected light pickup devices with light source and pickup centerlines tangential to the ware and perpendicular to each other, the pickup device having a vertically elongated scanning head.

w-dome .r' k/ i 1 SR t, K 3 639,067 I Ulkltbu Uibuwwu A -v 1--'Step11ens 1 1 Feb. 1, 1972 1541 GLASSWARE INSPECTION 3,030,516 4/1962Seavey ..250/223 B APPARATUS EMPLOYING FIBER- 3,069,553 12/1962Zoltanski. ..356/240 p c GUIQES 3,089,594 5/1963 Early ..209/111.73,188,478 6/1965 Binks ..250/219 [72] Inventor: Edward J. Stephens,Manchester, Conn. 3 244 9 4/1966 Steele et a]. 250/227 [73] Assignee:Emhart Corporation, Bloomfield, Conn. 312551357 6/1966 Kapafly 250/2273,265,901 8/1966 Schmeder ..250/223 123 Fllcdi J1me 29, 1970 3,287,56411/1966 GOl'C et 31.... ...250/223 B 2 App] 5 092 3,349,906 10/1967Calhoun etal; .356/240 3,365,699 1/1968 Foster ..356/240 Related U.S.Application Data 3,394,263 7/1968 Baker ..'.....356/240 {63]Continuation of Ser. No. 827,106, May 15, 1969,

abandoned, Continuation of Ser. No. 403,837, Oct. PmTmry Y 14, 1964abandone Assistant Lxammer-Omlle B. Chew, ll

Attorney-McCormick, Paulding & Huber [52] U.S. CL... ...356/240, 250/223B 1511 1m. 01. ..G01n 21/32 1 1 ABSTRACT [58] Field of Search ..356/240;250/223 B Optical glassware inspection apparatus with rotating upright56 R f d ware at an inspection station and fiber-o tic bundles em- I eerences ployed for light source and/or reflected light pickup mes UNITEDSTATES PATENTS with light source and pickup centcrlines tangential tothe ware and perpendicular to each other, the pickup device having a1,542,183 6/1925 Stembcrg... ..l28/398 vg ticany l ngated canning head.1,751,584 3/1930 Hansell ..178/6.7 2,643,767 1/1953 Baker ..356/240 3Claims, 8 Drawing Figures 5H site-6% PAIENIEB FEB H972 3.639.067

SHEET 1 UP 2 F/G. I MKS INVENTOR EDWARD J. STEPHENS GLASSWARE INSPECTIONAPPARATUS EMPLOYING FIBER-OPTIC GUIDES CROSS-REFERENCE TO RELATEDAPPLICATIONS This application is a continuation of application Ser. No.827,106 entitled GLASSWARE INSPECTION APPARATUS EMPLOYING FIBER OPTICGUIDES, filed May l5, I969; now abandoned, which application is in turna continuation of application Ser. No. 403,837 entitled GLASSWAREINSPEC- TION APPARATUS EMPLOYING FIBER OPTIC GUIDES, filed Oct. 14,I964, now abandoned,,all applications being in the name of Edward J.Stephens.

This invention relates to glassware inspection apparatus and has as itsgeneral object the miniaturization of elements such as light-receivingand source units in such apparatus.

In fulfillment of this object, fiber optic guides or bundles areemployed as light receiving and transmitting units and/or as lightsource units and a small but compact and yet highly efficient glasswareinspection apparatus is provided.

The drawings show preferred embodiments of the invention and suchembodiments will be described, but it will be understood that variouschanges may be made from the constructions disclosed, and that thedrawings and descriptions are not to be construed as defining orlimiting the scope of the invention, the claims forming a part ofthisspecification being relied upon for that purpose.

Ofthe drawings:

FIG. 1 is a schematic illustration in plan view ofa glassware inspectionapparatus embodying the present invention;

FIG. 2 is an enlarged fragmentary schematic illustration in plan view ofthe apparatus showing a light source unit and a light-receiving unit inassociation with an article of glassware;

FIG. 3 is a side view ofthe elements shown in FIG. 2;

FIG. 4 is a vertical section through a portion of a lightreceiving unitwhich includes a scanning head and is taken generally as indicated at4-4 in FIG. 2;

FIG. 5 is an end view of the scanning head of FIG. 4 and IS takengenerally as indicated at 55 in FIG. 2;

FIG. 6 is a vertical sectional view through an alternative form ofscanning head and light-receiving unit;

FIG. 7 is a vertical sectional view through several scanning heads andlight-receiving units in a further alternative embodiment oftheinvention; and

FIG. 8 is an enlarged schematic illustration in plan view similar toFIG. 2 but showing a further alternative embodiment ofthe invention.

Glassware inspection apparatus heretofore available has been generallysatisfactory but certain disadvantages have been encountered inoperation of the apparatus. Light-receiving units such as photoelectriccells and light source units have been relatively large and bulky so asto cause difficulty in arranging such elements particularly when settingup for a change in the type ofglassware under inspection. Tedious andtime-consuming operations involving cut and try methods have beenemployed in such setup procedures and very often the size and bulkinessof the elements has resulted in interference where two such elementsmight desirably have occupied the same space. Thus, there have beenobvious limitations upon the number oflight source and receiving unitsusable, this arising from the interference problems encountered, and incertain setup operations it has been found impossible to illuminate andview all required portions of an article of glassware at one time. Stillfurther, the versatility of the apparatus has left much to be desired inthe accommodation of certain types ofglassware. v

As will be explained more fully hereinbelow, fiber optic guides orbundles provide a means of viewing relatively large areas on articles ofglassware with very small viewing or lightreceiving devices. Any and allparts or portions of articles of glassware can thus be viewed withoutthe problems of physical interference of viewing elements and highlyefficient detection of defects is yet achieved. Close positioning of thefiber optic viewing elements and a wide angle of vision of the elementscontribute to this latter achievement such that effectiveness andefficiency of operation exceeds that of prior.inspection apparatus.

In accordance with the present invention, fiber optic guides or bundlesare employed as light-receiving and/or light sources elements and theymay be incorporated in substantially any and all prior inspectionapparatus. Baker Pat. No. 2,643,767 and Miles et al. Pat. No. 2,902,151represent prior inspection apparatus wherein the teaching of the presentinvention may be employed as does application Ser. No. 382,837, filedJuly 15, I964, and entitled MECHANISM FOR HANDLING GLASS CONTAINERS."For purposes of illustration only and without limitation, apparatus ofthe general type shown in Baker Pat. No. 2,643,767 is employed in theschematic of FIG. 1 and is described in general terms hereinbelow.

A turntable 10 may be rotated or indexed intermittently in acounterclockwise direction by conventional means, not-(' shown, wherebyto move articles of glassware 12 from at least one ware inspectionstation to a ware rejection station. Thus, the turntable 10 serves as aconveyor and transports articles of glassware 12in succession to a wareinspection station A and a ware rejection station B, an article ofglassware 12a being shown at the inspection station A and an article ofware 12b being shown at the rejection station. Glassware may, of course,be loaded onto the turntable either manually or automatically by meansnot shown and acceptable ware similarly removed from the table.Defective glassware is removed from the table at the rejection station Bas will be described hereinbelow.

At the inspection station A at least one light source unit is providedas at 14 and at least brie elongated flexible light receiving andtransmitting device is employed in accordance with the invention. Such adevice is shown at 16 in FIG. 1 and comprises a fiber optic guide orbundle which extends from a position adjacent the article of glassware12a to a control unit 18. The control unit 18 includes a light detectorsuch as a photoelectric cell or photodiode and the end portion of thereceiving and transmitting device 16 is operatively associated with thedetector so as to transmit light thereto. A broken line 20 may be takenas representing the position of a light detector in the control 18.Associated with the light detector 20 in the control 18 in theconventional manner is an amplifying means which may comprise apreamplifier and an amplifier and a means, which may comprise athyratron, for operating a rejection mechanism. All of these elementsare conventional in prior glassware inspection apparatus need not bedescribed in detail here.

Referring further to the inspection station A, a means for effectingrelative rotation between an article of glassware such as and alight-receiving end portion of the receiving and transmitting device 16is provided. While the invention is not so limited, the article ofglassware is rotated in FIG. I in a conventional manner and the lightguide 16 is maintained in a fixed position as is the light source unit14. Glassware-supporting rollers 22 are provided for cooperation with asomewhat larger ware rotating roller 24. Said rollers may beconventional as with means for driving the same, not shown.

At the rejection station B, a reciprocable plunger 26 is operated onsignal from the light receiving and transmitting device 16 and thecontrol 18 to reject articles of glassware such as 12b when defects areviewed therein by the said device 16. The plunger 26 is shown connectedwith the control I8 schematically by the broken line 28 and is adaptedto urge the defective articles of glassware 12b leftwardly from theturntable l0 and onto a downwardly inclined chute 30. Plunger 26 is ofcourse maintained in a retracted position so as not to interfere withthe passage of acceptable articles of glassware to an unloading station.

As best illustrated in FIGS. 2 and 3, the light-receiving end portion ofthe flexible light receiving and transmitting element 16 preferablyincludes a scanning head such as the head 32. The receiving andtransmitting member 16 in FIG. 2 may comprise a fiber optic guide orbundle as mentioned and may be of in a fan configuratio nintheflscanninghead 32. There is in fact 7 no appreciable space betweenfibers and several layers of fibers may be found even in the narrowhorizontal dimension in FIG. 5, this being due to the comparativelysmall size of the fibers. Still further with respect to field of vision,it is to be ob served that a 60 field is common with fiber optic guidesor bundles as indicated at 36 in FIG. 2 and as much as a 90 field hasbeen obtained. For this reason a horizontally narrow and verticallybroad scanning head such as shown in FIG. can provide highly efficientoperation. A slight loss in the field of vision in the horizontal planecan in fact be advantageous in the elimination of extraneous light and"noise" in the apparatus. The broad field of vision in the verticalplane is of course advantageous in covering a large area on the articleof glassware as indicated in FIG. 3. Actual width of the fiber band inFIG. 5 may be on the order of 0.025 inch and actual height slightly lessthan five-eighths ofan inch.

Still referring to FIGS. 4 and 5 in particular, the scanning head 32will be seen to include a housing 38 and g pgttjpg compoundill disposedwithin the housing and securing the fibers 34, in the desired position.The potting compound may comprise an epoxy resin Alternatively, noseparate housing such as 38 in aybe provided and instead, the pottingcompound itself may be employed as the housing for the scanning head.

The light source at 14 comprises a housing or shield 40 which contains asmall low-wattage bulb and a focusing lens in accordance with thepresently preferred form of the invention. A bracket may be provided at42 for securing the light source unit in position.

The location of the light-receiving and light source units may varywidely with respect to each other and with respect to the article ofglassware within the scope of the present invention. Various types ofdefects in the article of glassware will of course require differentlocations of these elements. The particular arrangement of elementsshown in FIG. 2, however, is highly cfficient particularly in thedetection of vertical and angular checks such as 42 in the article ofglassware 12a. The said article of glassware comprises a baby food jarand the arrangement of light source and receiving units shown has beenfound to provide highly efficient operation and results with jars ofboth the lug and screw thread type.

In the particular arrangement of FIG. 2, the beam of light provided bythe light source unit 14 is focused as mentioned above and is directedapproximately horizontally and tangentially toward the lug or threadsurface as shown. A centerline 44 of the beam of light which is castupon the article of glassware preferably extends slightly closer to theinnerjar surface than the outer jar surface as shown. A centerline 46 ofthe receiving unit or scanning head 32 is shown extending at rightangles with respect to the centerline 44 and is preferably approximatelytangential and slightly closer to the inner surface ofthe lug or threadsection as shown. With this arrangement, it is thought that the jaritself may serve somewhat in the na ture of a light guide or bundle suchthat the beam of light emitted by the light source 14 travels throughthe lug or thread portion of the jar around the corner and is reflectedfrom defects such as 42 to the scanning head 32. It is believed furtherthat a quiet zone" exists in the area where the defects 42 are shownsuch that highlights from the lugs or threads do not significantlyaffect the scanning head and the other control elements so as to providea high noise level. Instead, a desirably low noise level is achieved anda high signal-to-noise ratio is provided in the control.

Still with regard to the arrangement of elements, but apart from thespecific arrangement of FIG. 2, it is thought highly desirable in allinstances to provide the light-receiving end portion of the fiber opticguide or bundle in very closely spaced relationship with the article ofglassware. It is presently believed that the scanning head orlight-receiving end portion of the guide or bundle should be placedsubstantially as close as the eccentricity of the article of glasswarewill permit. An outer limit in placement of the scanning head orlight-receiving end portion is believed to fall at approximately l inchfrom the article of glassware. Placement of the scanning head orlight-receiving end portion of the guide or bundle in close proximity tothe article of glassware is believed to contribute to the excellentnoise to signal ratios achieved with the inspection apparatus. Due tothe comparatively wide angle of vision of the scanning head or endportion of the fiber optic guide or bundle, reflected lightrays arereceived as required and yet the close spacing precludes theintroduction of excessive extraneous light as might otherwise causesubstantial noise. Extraneous light may arise, for example, fromreflection of light from machine or apparatus elements.

Referring now particularly to FIG. 6, it will be observed that a fiberoptic bundle or guide 16a has an associated scanning head 32a. Thescanning head 32a is similar to the scanning head 32 described above butemploys the potting compound 40a as a housing and includes a contouredrather than a planar front or scanning end surface48l lheTohTo'ui e dsurface 48 may be provided by magl ining aftgr the scannin head has beenpotted and'tfieco our E in NM form at least 36111 surfac'bf an adjfi ceiif ar e of glassware 50, With this arrangement, the light-receiving endportions ofthe fibers or the scanning head surface 48 may be disposedeven in closer proximity to the outer surface of an article of glasswareto provide for excellent reception oflight rays reflected from defectsand for elimination ofextraneous light.

In FIG. 7 there is shown a construction wherein substantially the entiresurface of an article of glassware can be inspected with the use offiber optic guides or bundles. Scanning heads 50, 52, 53 and 54 areprovided each with a contoured front end surface adapted to conformclosely to ih e configuration of the adjacent surface of anarticleo'f'glassware such as 56.

In FIG. 8 there is shown an alternative embodiment of the presentinvention wherein all elements may correspond exactly with thosedescribed above for FIG. 2 except for the light source 14. A secondfiber optic guide or bundle 58 is provided in this embodiment and isarranged to transmit light to an article of glassware from a lightsource not shown. The light source may be conventional and the endportion of the fiber optic bundles 58 adjacent the article of glasswaremay be held by a suitable bracket to direct light tangentially on thearticle as mentioned, or the direction of a light beam cast by the guideor bundle may of course be conveniently altered. Optionally, a focusinglens may be provided at the end of the fiber optic guide or bundlebetween the end portion thereof and the article of glassware and a smalllens housing is shown accordingly at 60.

From the foregoing it will be apparent that a desirably small andcompact inspection apparatus has been provided. Due to the very smallsize of the light source and receiving units employed. an almostlimitless variety of arrangements of such units is obtainable.Inspection can thus be undertaken for substantially all known types ofdefects and many if not all defects may be examined for in asimultaneous operation.

The apparatus is substantially more versatile than prior comparativelylarge and bulky apparatus. Due to the comparatively wide field of visionof the fiber optic guides or bun dles, precise location of the receivingend portion of a bundle or a scanning head is not essential as in thecase of a large focused photoelectric cell. In one inspection procedureinvolving baby food jars of the type shown, a 5 minute setup time wasrequired with the present apparatus whereas conventional inspectionapparatus utilizing the comparatively large and bulky inspectionelements aforesaid would have required two or three separate setupsrequiring a total of4 to 5 hours of setup time. Moreover, a single lightsource and a single receiving unit were employed with the presentapparatus. Three photticells and two light sources would have beenrequired with the older apparatus.

Finally, the use of the fiber optic guides and bundles and the closespacing and scanning head arrangements ofthe invention permit the use ofextremely low-wattage bulbs in the light sources with correspondingreduction in power requirements of the apparatus. High-intensity lightis not needed due to the excellent light pickup characteristics and thebroad field of vision of the fiber optic guide receiving end portions.Such use of low-intensity light is also-believed to contribute to theexcellent signal-to-noise ratios achieved with the apparatus.

1 claim:

1. Glassware defect inspection apparatus comprising a conveyor fortransporting ware in an upright attitude from at least one wareinspection station to a rejection station, ware rejection means at saidrejection station, at least one light source at said inspection stationarranged to cast a beam of light on a substantially horizontalcenterline which is generally tangential with respect to an article ofglassware at the station, at least one light receiving and transmittingdevice at said inspection station, said receiving and transmittingdevice comprising an elongated flexible member which includes aplurality of light-transmitting fibers and a narrow vertically elongatedscanning head disposed at one end of said member and adjacent an articleof glassware at the inspection station so as to accept reflected lightfrom defects in the ware, said scanning head having fiber ends exposedand facing toward the ware along a substantially horizontal centerlinewhich is generally tangential to the glassware and generallyperpendicular to the centerline of the aforesaid beam of light so as toreceive reflected light from defects in the ware, means effectingrelative rotation between an article of glassware at said inspectionstation and said scanning head of said elongated member a light detectoroperatively associated with an opposite end portion of said elongatedreceiving and transmitting device, and means connected with and operatedby said detector to cause said rejection means to operate when defectiveglassware is transported to said rejection station from the inspectionstation.

2. The combination in glassware inspection apparatus as set forth inclaim 1 wherein said centerline of said beam oflight is w tangentialwith respect to an inner surface of an article of glassware at theinspection station.

3. The combination in glassware inspection apparatus as set forth inclaim 1 wherein the vertical dimension of the aggregate exposed fiberend area at said scanning head is at least six times the horizontaldimension thereof.

1. Glassware defect inspection apparatus comprising a conveyor fortransporting ware in an upright attitude from at least one wareinspection station to a rejection station, ware rejection means at saidrejection station, at least one light source at said inspection stationarranged to cast a beam of light on a substantially horizontalcenterline which is generally tangential with respect to an article ofglassware at the station, at least one light receiving and transmittingdevice at said inspection station, said receiving and transmittingdevice comprising an elongated flexible member which includes aplurality of lighttransmitting fibers and a narrow vertically elongatedscanning head disposed at one end of said member and adjacent an articleof gLassware at the inspection station so as to accept reflected lightfrom defects in the ware, said scanning head having fiber ends exposedand facing toward the ware along a substantially horizontal centerlinewhich is generally tangential to the glassware and generallyperpendicular to the centerline of the aforesaid beam of light so as toreceive reflected light from defects in the ware, means effectingrelative rotation between an article of glassware at said inspectionstation and said scanning head of said elongated member, a lightdetector operatively associated with an opposite end portion of saidelongated receiving and transmitting device, and means connected withand operated by said detector to cause said rejection means to operatewhen defective glassware is transported to said rejection station fromthe inspection station.
 2. The combination in glassware inspectionapparatus as set forth in claim 1 wherein said centerline of said beamof light is tangential with respect to an inner surface of an article ofglassware at the inspection station.
 3. The combination in glasswareinspection apparatus as set forth in claim 1 wherein the verticaldimension of the aggregate exposed fiber end area at said scanning headis at least six times the horizontal dimension thereof.